Elevator.



No. 535,454. v Patented Oct. 24, I899. M. A. WHEATON.

E L E V A T 0 R (Application filed June 1, 1898.)

4 Sheets-Sheet 2,

(No Model.)

Wef

ww wv I Patented Oct. 24 I899.

M. A. WHEAT-0N.

ELEVATOR. (Application filed June}, 1898.)

4 Sheets'-Sheet 3.

(No Model.)

THE NORRIS PETERS c0. m-ammmm.v WASHINGTON, n c.

Nrrnn MILTON A. VVIIEATON, OF SAN FRANCISCO, CALIFORNIA.

ELEVATOR.

SPECIFICATION formingpart of LettersPatent No. 635,454, d td O t b 24, 1899.

Application filed June 1, 1898- Serial No. 682,267. (No model.)

To all whont it may concern:

Be it known that I, MILTON A.WHEATON, a citizen of the United States, and a resident of the city and county of San Francisco, in the State of California, have invented certain new and useful Improvements in Elevators, of which the following is a specification.

My invention consists of improvements in that class of elevators in which the elevatorcage is raised and lowered by means of an endless driving-cable that passes around two independently-operating driving-pulleys and always runs continuously in the same lines or course of direction and in which elevators the cage is made to ascend and descend by changin g the relative rates of oircu inferential speed of the two driving-pulleys.

In the drawings, Figure 1 shows an elevator with my improvements incorporated therein. Fig. 2 is a plan of the construction shown in Fig. 1. Fig. 3 is a diagram representing in detail and on a larger scale my said improvements detached from the elevator. Fig. 4: is a view similar to Fig. 3, but showing my improvements in a simpler form and with a less number of parts. Fig. 5 is a broken elevation illustrating still another form of application of my improvements. Fig. 6 is a plan taken through the line y y of Fig. 5.

In the drawings similar letters of reference refer to corresponding parts.

B and O are two driving-pulleys, which may be driven by any suitable motor, several kinds of which are well known and in common use for operating elevators and therefore need not be described here.

As shown in Figs. -1 and 2 of the drawings, the elevator is constructed with corner-posts P P and two middle guide-posts R and Q. It also has two driving or motor pulleys B and (l, a cage A, a counterweight W, two overhead sheaves G and M, a hoisting or lifting cable L, passing over the sheave M and connecting the cage to the counterweight, and another suspension-cable F, that passes over the sheave Gr and connects the counterweight with a slide E. The slide E is fitted to run up and down between one of the corner-posts P and the middle guide-post R. Both of said posts serve to guide the slide E and keep it in its proper place. Between the same guidepost R and the other post P is the counterweight W, which is also fitted to slide up and down between said posts and is guided in its up-and-down movements and kept in its place by said posts. The said slide E, to which the left-hand end of the cable F is fastened, is placed between one of the corner-posts P and the middle post R and is fitted and arranged to move up and down in suitable longitudinal'grooves therein. (See Figs. 1 and 2.) In a similar manner the counterweight W, which is attached to the other end of the cable F, is shaped and adapted to slide between the middle post R and another of the corner-posts P, located at the right of the elevator-frame, the said counterweight sliding in longitudinal grooves in said posts, all as shown in Figs. 1 and 2.

In myilnprovement I use two trains of traveling pulleys a b 0 cl and efg h. The first of these trains is mounted upon and carried by the slide E, which is suspended at the lefthand end of the cable F, and the second of said trains is mounted upon and carried by the counterweight W, which is suspended at the other end of said cable F, as shown in Fig. 1. Besides these two trains of traveling pulleys I employ two series of pulleys ij 7a and Z m n, which remain so nearly stationary that I designate them as standing pulleys. These standing pulleys are combined with said traveling pulleys and the endless cable D in such .a Way as to form on each side of the drivingpulleys what may be fairly termed a fall and tackle. These two falls and tackles act jointly together, as one will not be operative without the other, and together they form a double fall and tackle. The endless cable D passes around both of the driving-pulleys and also around all of said traveling and standing pulleys, as hereinafter specifically described. The said double fall and tackle is constantly under the joint control of the two driving-pulleys B and O. Other ways of mounting my trains of pulleys will readily oc-* our to any skilled mechanic without departing from my invention. The two trains of standing pulleys 'i j k and Z 17?. 12 may have a slight up-and-down-movement for the purpose of keeping the endless cable taut when it shrinks or stretches, and I therefore mount them upon their own respective slides O and N. The slide 0 is located below the slide E,

invention. only the two traveling pulleys a and (Z, and

and the slide N is located below the sliding counterweight IV, and all are located in the same vertical plane. The slide 0 is fitted between the same posts as the slide E, and the slide N is fitted between the same posts as the counterweight \V. The slides O and N are made sufficiently heavy to serve as tension-weights and keep the endless cable D under such an amount of tension and strain as will make it adhere to the driving-pulleys I and G with sufficient frictional contact to insure its being driven by those pulleys. Thus these sliding weights 0 and N are made to perform the duty of supporting the frictionpulleys that are mounted upon them and also the additional duty of automatically keeping taut the endless driving-cable D.

J is a friction-pulley fixed over the drivingpulley B, and K is a friction-pulley fixed over the driving-pulley C. \Vhen these frictionpulleys are used, each of them is formed with a single groove in its periphery,and the driving-pulleys B and C are formed with two grooves in each of their peripheries. The endless cable D is wound around the lower part of each of the driving-pulleys, then over the upper part of each of the friction rollers, and from thence down around the lower part of the driving-pulleys a second time. This arrangement makes the endless cable pass twice around the lower parts of the drivingpulleys,and thereby doubles its frictional contact therewith and makes the cable less liable to slip on the peripheries of the driving-pulleys while the elevator is doing its work.

I operate my tension apparatus by means of a yielding weight that is suspended in one or more of the bights of the endless cable, where it will move upward and downward as the cable shrinks or stretches, and thus automatically accommodate itself to all variations in the length of the cable that will occur while the cable is doing its work, and thus keep the cable at one constant degree of tension.

The vertical movement of the tension-slides O and N is only so much as will compensate for the shrinkage and stretching of the endless cable and keep it taut. Obviously either one of these tension sliding weights 0 or N may be used successfully without the other; but if only one is used its vertical movements will be twice as much as it will be when both are used. Such use of a single sliding tension-weight is substantially shown in Fig. i of the drawings. Said Fig. a illustrates one of the simplest forms of the application of my In this figure the slide E carries the counterweight \V carries only the two traveling pulleys c and lb. At the left of Fig. 4 there is only the single lower standing pulley t', which is fixed in its position and has no vertical movement whatever. On the right of Fig. i there is only the single standing pulley Z. To this pulleylthere is hung the tension-weight T, which may slide vertically in the guideway shown in the frame-timber S and c0rner-post P below the counterweight IV. The said slide E and counterweight IV, as in the previously described construction, are arranged to move vertically between the corner-posts P and the middle post R and are respectively attached to the opposite ends of the cable F, that passes over the sheave G. The vertical movement of the pulley Z and tension-weight T (shown in Fig. 4) is very slight, being only as much as is required to keep the endless cable taut. In Fig. 4 the driving-pulleys B and C and friction-pulleys J and K are the same as before described. In Fig. 4 the endless cable D is wound in a continuous course, as indicated by the arrows, being passed around both driving-pulleys l3 and O and thence to and around the frictionpulleys J and K and taking simple turns around the upper sides of the traveling pulleys a d and e71, and around the under side of the standing pulleys i and Z.

The principal advantages gained by my invention are well illustrated in Fig. 4, viz: First, there is a double fall and tackle on opposite sides of the driving-pulleys, by means of which purchase-power is gained for them; second, additional frictional contact of the cable D with the driving-pulleys I3 and C is obtained by the application of the frictional pulleys J and K; third, a constant uniform tension of the driving-cable D is obtained by the suspended tension-weight, which is free to move up and down, and thus accommodate itself to the stretching and shrinking of the driving-cable D, and, fourth, the purchase-power that is gained by the use of the said double fall and tackle serves as an inherent brake that resists to a greater or less extent the naturaltendency of the load to make undesired descents. This tendency of the load to make undesired descents is resisted somewhat by the friction which the load must overcome in making its descent. The said purchase-power combines with and multiplies the said frictional resistance to the descent of the load, and there is thus formed an inherent brake that is very valuable in preventing,or at least in assisting to prevent, undesired descents of the loads which the driving-pulleys must otherwise sustain when the elevator-car is held suspended in a stationary position. This inherent brake always operates to lessen the labor of the driving-pulleys, and it never operates to increase such labor. The more times this double fall and tackle is multiplied the greater will be the said purchase-power and the greater will be its effect as an inherent brake in preventing the load from descending by force of its gravity. Where the purchasepower that is obtained by said double falls and tackles is as great as that which will be obtained by using the number and arrangement of parts shown in Figs. 1 and 3, the said purchase-power, reinforced, as it always will be,by the friction of the mechanism that tends to prevent the load from descending, will constitute a sufficient inherent brake to hold an Ordinary load in suspense without any assistance from the said driving-pulleys, and there will be saved all the consumption of motive power that is now required to hold the load in stationary suspension.

The friction-pulleys J and K in the construction shown in Figs. 1 and 3 are in a fixed position, so that they always preserve the same relation to the driving-pulleys B and 0. They are mounted in any suitable manner. In Fig. 1 they are shown pivoted to the motor-frame. They, together with the driving-pulleys, above which they are respectively mounted, are placed at one side of the elevator-shaft, 'so as to be in the same general plane with the traveling pulleys, the standing pulleys, and the endless cable.

Figs. 5 and 6 represent a modification of the apparatus as arranged and shown in Fig. 4. In Figs. 5 and 6 the winding of the endless cable is similar to that followed in Fig. 4 and calls for the same number of traveling and standing pulleys, although the said cable is broken and the two upper traveling pulleys a and e do not appear, the traveling pulleys d and h only being shown as respectively attached to the slide E and counterweight W. The said slide and counterweight are also broken, but otherwise appear placed between the corner-posts P and the middle post R, as in the other drawings. In said Figs. 5 and 6 both of the lower standing pulleys are in a fixed position and neither of them has any vertical motion whatever, the tension of the endless cable being obtained by applying means to make the two friction-pulleys J and K movable and attaching to them a yielding tension-weight as follows: The said frictionpulleys are located, as before described, one above each of the respective driving-pulleys l3 and 0. Both the friction pulleys are mounted upon a slide X, that is fitted to 0perate between the posts U and V and which is suspended from one end of a cable Z, that passes over a stationary sheave Y and has suspended at its other end a tension-weight T. The slide X has a suitable slot in its center that allows it to surround the shaft of the upper driving-pulley O and move freely up and down without producing any interference with said shaft The downward pull of the tension-weight T, which is suspended on one end of the rope Z, draws the other end .of the rope upward and with it the slide X, which is suspended thereon, and the friction-pulleys J and K, which are carried by the said slide. As these friction-pulleys are drawn upward they increase the distance and length of the cable between themselves and the drivingpulleys, and thereby take up all the stretch of the cable and keep it constantly at the proper tension. In case any shrinkage of the cable occurs the friction-pulleys J and K will be drawn downward by its shortening and the sion and strain equal to its own gravity upon the cable.

The friction-pulleys J and K are not an absolute necessity, as my other improvements will operate without them. Their use, however, is of great advantage to the elevator, and for this reason I have provided for their insertion and use as a part of my improvements.

The endless cable D is preferably wound in the manner illustrated in Fig. 3, following the course indicated by the arrows therein, to wit: Commencing for a starting-point at the lower edge of the driving-pulley O and carrying the cable in the direction indicated by the arrow atthat point to the left and upward, passing it aroundthe friction-pulley K, and thence downward on the right hand of the pulleys K and O and around underneath the pulley O in a second groove thereof, thence upward andover the traveling pulley a, thence downward on the left hand of the pulleys to and around the lower side of standing pulley k, thence upward and around the upper side of traveling pulley c, thence downward and around the lower side of standing pulley 'i, thence upward from the right side of said pulley t' to the left side of traveling pulley d, thence passing around the upper side of said pulley d downward and around the lower side of standing pulleyj, thence upward and around the upper side of traveling pulley b, thence downward to and around the lower side of driving-pulley B, thence upward around the upper side of friction-pulley J and downward around the lower side of drivingpulley B in a second groove therein, thence upward around the upper side of traveling pulley f, thence downward along the righthand side of the pulleys to and around the lower side of standing pulley m, thence upward and around the upper side of traveling pulley h, thence downward from the righthand side of said pulley h to the left-hand side of standing pulley Z, thence around the lower side of said pulley land upward to and around the upper side of traveling pulley g, thence down ward to and around the lower side of standing pulley n, thence upward to and around the upper side of traveling pulley e, and from thence to the lower side of the driving-pulley O, which is the starting-point taken.

The number of traveling and standing pulleys may be diminished or increased, as the constructor may desire, to diminish or increase the purchase-power of the driving-pulleys. In Figs. 4 and 5 the traveling pulleys between a and d and between eand h are dispensed with, as are also all of the said standing pulleys, excepting onlyt' and Z. Any desired number of traveling pulleys may be inserted between the traveling pulley b and the traveling pulley d. In such case, however, there must be an equal number of traveling pulleys inserted between the traveling pulleys f and h, and there must also be a corresponding number of standing pulleys added below in order to preserve the operative integrity of the said mechanism, which I have called the double fall and tackle and which is created by the use of said endless cable with the said series of driving, traveling, and standing pulleys.

In an elevator made as herein described the cage or load will remain stationary when the two motor-pulleys B and 0 both rotate at the same rate of circumferential speed; but when one of such motor-pulleys rotates at a greater rate of circumferential speed than does the other the cage or load will be either raised or lowered, according to which one of the pulleys has the greater amount of circu 1nferential speed.

By the term circumferential speed I mean the rate of speed at which the circumference of each of the pulleys runs, without regard to the number of revolutions that it may make.

\Vhat I claim, and desire to secure by Letters Patent of the United States, is

1. In an elevator, the combination of two independently-operated motor-pulleys and an endless cable that is placed upon and driven by said motor-pulleys, arranged so that the endless cable will run constantlyin oneline of direction and each respective motor-pulley will rotate constantly in one direction, and the stopping or moving of the cage or load is controlled by equalizing or varying the relative rates of the circumferential speed of the two motor-pulleys, substantially as herein described, a series of friction-pulleys around which said cable passes and slides on which said pulleys are journaled, said cable, pulleys and slides forming a double fall and tackle, substantially as described.

2. In an elevator, the combination of two independently-operated motor-pulleys and an endless cable that is placed upon and driven by said motor-pulleys arranged substantially as herein described so that the endless cable will run constantly in one line of direction and each respective motor-pulley will rotate constantly in one direction, and the stopping or moving :of the cage or load is controlled by equalizing or varying the relative rates of the circumferential speed of the two motorpulleys, substantially as herein described, of a double fall and tackle which is arranged and applied as herein described so that it will furnish a purchase-power to assist the driving-pulleys in raising and supporting the load, and will also operate as an inherent brake to counteract to a greater or less extent the tendency of the load to be carried downward by the force of its gravity.

3. In an elevator the combination of two independently-operated motor-pulleys,a double fall and tackle constructed substantially as herein described and in which there is an endless cable so arranged that it passes around the several friction-pulleys contained in said fall and tackle and is also placed upon and driven by said motor-pulleys as herein described and so that the said endless cable will run constantly in one line of direction and each respective motor-pulley, as well also as each respective friction pulley around which the said endless cable passes will rotate constantly in one direction, and the stopping or moving of the load will be controlled by equalizing or varying the relative rates of the circumferential speed of the two motorpulleys, and one or more tension-weights suspended in said endless cable substantially as and for the purposes herein set forth.

4. In an elevator, the combination of two independen tly-operated motor-pulleys and an endless cable that is placed upon and driven by said motor-pulleys arranged substantially as herein described so that the endless cable will run constantly in one line of direction and each respective motor-pulley will rotate constantly in one direction and the stopping or moving of the load will be controlled by equalizing or varying the relative rates of the circumferential speed of the two motor-pulleys, substantially as herein described, with the traveling plate E, having two or more pulleys attached thereto,the traveling weight IV, having two or more pulleys attached thereto, and the two sets of cable-pulleys placed respectively below the plate E and the weight W, substantially as herein described.

5. In an elevator, the combination of two independently-operated motor-pulleys and an endless cable that is placed upon and driven by said motor-pulleys arranged substantially as herein described so that the endless cable will run constantly in one line of direction and each respective motor-pulley will rotate constantly in one direction and the stopping or moving of the load will be controlled by equalizing or varying the relative rates of the circumferential speed of the two motor-pulleys, substantially as herein described, with one or more pulleys suspended near one of said motor-pulleys so that the endless cable may pass around both the motor-pulley and the pulley so suspended, and means for moving the latter toward and away from the motor-pulleys so as to compensate for the stretching and shrinking of the endless cable and keeping it at a constant uniform tension, substantially as herein described.

6. In an elevator, the combination of two independently-operated motor-pulleys and an endless cable that is placed upon and driven by said motor-pulleys arranged substantially as herein described so that the endless cable will run constantly in one line of direction and each respective motor-pulley will rotate constantly in one direction and the stopping or moving of the load will be controlled by equalizing or varying the relative rates of the circumferential speed of the two motor-pulleys, substantially as herein described, with two friction-pulleys located one above each of said motor-pulleys respectively, the end-' less cable passing around said motor-pulleys and also around said friction-pulleys, the slide X with the said two friction-pulleys attached thereto, and means for moving the same so as to preserve a constant uniform tension upon said endless cable, substantially as herein described.

7. In an elevator, the combination of two ind'epend ently-operated motor-pulleys and an endless cable that is placed upon and driven by said motor-pulleys arranged substantially as herein described so that the endless cable will run constantly in one line of direction and each respective motor-pulley will rotate constantly in one direction and the stopping or moving of the load will be controlled by equalizing or varying the relative rates of the circumferential speed of the two motor-pulleys, substantially as herein described, a cage or load that is to be raised or lowered, a counterweight, two trains of traveling pulleys, the first of which trains is attached to the counterweight and is carried in bights of the endless cable and the second of which trains is carried in other bights of the endless cable, two series of standing pulleys corresponding to the said two trains of traveling pulleys and likewise carried in bights of the said endless cable, two sheaves, a cable passing over one of said sheaves and connecting the counterweight with the cage in such a manner that when the counterweight descends it will draw the cage upward, and when the counterweight ascends it will allow the cage to descend by its own gravity, and another cable passing over the other of said sheaves and connecting the counterweight with the second train of said traveling pulleys, the whole combined and operating substantially as herein described.

MILTON A. WHEATON. Witnesses:

GEO. T. KNOX, H. J. LANG. 

